Superconductivity in Fullerides
نویسنده
چکیده
Experimental studies of superconductivity properties of fullerides are briefly reviewed. Theoretical calculations of the electron-phonon coupling, in particular for the intramolecular phonons, are discussed extensively. The calculations are compared with coupling constants deduced from a number of different experimental techniques. It is discussed why the A3C60 are not Mott-Hubbard insulators, in spite of the large Coulomb interaction. Estimates of the Coulomb pseudopotential μ, describing the effect of the Coulomb repulsion on the superconductivity, as well as possible electronic mechanisms for the superconductivity are reviewed. The calculation of various properties within the Migdal-Eliashberg theory and attempts to go beyond this theory are described.
منابع مشابه
Conductivity and Superconductivity in C60 Fullerides
Conductivity and superconductivity of Cm fullendes are reviewed, and the
متن کاملPolymeric alkali fullerides are stable in air
Infrared transmission, electron spin resonance, and X-ray diffraction measurements show unambiguously that RbC60 and KC60 are stable in air, in contrast to Rb6C60 which decomposes rapidly upon exposure. The specimens studied transform into pure C60 and other byproducts when heated above 100◦C, approximately the temperature of the orthorhombic-fcc phase transition. The stability of these compoun...
متن کاملUnified understanding of superconductivity and Mott transition in alkali-doped fullerides from first principles
Alkali-doped fullerides A 3C60 (A = K, Rb, Cs) are surprising materials where conventional phonon-mediated superconductivity and unconventional Mott physics meet, leading to a remarkable phase diagram as a function of volume per C60 molecule. We address these materials with a state-of-the-art calculation, where we construct a realistic low-energy model from first principles without using a prio...
متن کاملExotic s-wave superconductivity in alkali-doped fullerides.
Alkali-doped fullerides (A3C60 with A = K, Rb, Cs) show a surprising phase diagram, in which a high transition-temperature (Tc) s-wave superconducting state emerges next to a Mott insulating phase as a function of the lattice spacing. This is in contrast with the common belief that Mott physics and phonon-driven s-wave superconductivity are incompatible, raising a fundamental question on the me...
متن کاملSurface Hubbard U of alkali fullerides
We report a combined photoemission spectroscopy (PES) and inverse photoemission spectroscopy (IPES) study of distilled, phase pure films of C60 and the monomeric fullerides Cs6C60, Cs4C60 and fcc RbC60. The separation between the highest energy PES and lowest energy IPES features, which is a measure of the barrier to hopping, is 1.45 eV in Cs4C60 and 0.7 eV in RbC60 . This difference is large e...
متن کامل